r17.x pre-processing update - ansys · 1 © 2016 ansys, inc. october 6, 2016 ansys confidential...

1 © 2016 ANSYS, Inc. October 6, 2016 ANSYS Confidential

R17.x Pre-processing Update

Maciej Ginalski


17.x Release

CFD Meshing

Courtesy Materialise


ANSYS CFD meshing solutions overview

• ANSYS continues to develop three products for CFD meshing

– Fluent Meshing (formerly TGrid)

– ICEM CFD (Hexa and Tetra/Prism)

– ANSYS Workbench Meshing

• These three products share underlying executables and have common functionality in many areas

• But on-going strengths and weaknesses remain

• Hence ANSYS have decided to simplify the licence arrangements


ANSYS CFD consolidated meshing options

• In 2015 (R16.1), ANSYS streamlined licencing for its CFD meshing tools

• Our four meshing tools are now available through licences of:

– ANSYS CFD

– ANSYS CFD PrepPost, ANSYS Meshing

– ANSYS CFX, ANSYS CFD-Flo

– ANSYS Fluent

– ANSYS Polyflow

• If you have legacy meshing licences (ICEM CFD, TGrid, CFX-CAD2Mesh, Fluent Solver, CFX Solver…) speak to your account manager about your migration options


ANSYS Tools Span the Breadth of Requirements

Class 1 Class 2 Class 3 Class 4 Class 5

Geometry Corruption Very High High Low Medium Medium

Geometry Complexity (# faces, parts or bodies)

> 1,000 100 to 1,000 100 > 100 parts < 1,000

Typical Applications Automotive & Aerospace UTM

Any Any Any Aerospace, Turbo, Chemical &

Material Proc.Built Environment

% of Applications

Fluent Meshing

Workbench Meshing

ICEM CFD

SpaceClaim can push models from Class 1 to Class 3 with low man-effort!


ANSYS Meshing @ R17.x

Fluent Meshing

• Advanced unstructured meshing (Tet, HexCore, CutCell, Poly with prisms)

• Surface wrapper for complex/dirty CAD

• Scriptable in Workbench

WB Meshing

• Native hybrid meshing in Workbench

• Good for anisotropic geometries

• Persistent in Workbench without need of scripts

ICEM CFD

• Advanced hex meshing

• CAD tolerant OCTREE

• Scriptable in Workbench

Shared Libraries

CFD & MechanicalMultiphysicsCFD


WB Meshing Highlights in 17.0 for CFD Users

• Performance improvements• Linux & other improvements• Mesh transfer to Fluent

• Better meshing status• Folders for meshing controls• Contact match mesh • Improved diagnostics• Improved criterion based selections• Hex meshing improvements• Improved ICEM CFD Interactive

blocking


Repair overlapping contact regions

• Repair Overlapping Contact Regions• Finds contact regions where an entity is in multiple contacts (when

exporting to Fluent or CFX this is considered “overlapping”)• Fixes contact regions by suppressing original contact regions and

creating new “Repaired” contact regions that do not overlap. • Overlapping cases that have cyclic redundancies are suppressed.

Overlapping contactssuppressed

Repaired contacts

AB

C

In cyclic redundant case: A // B, B // C, A // CSince there are no unique pairs, Fluent/CFX don’t support

this case, so all 3 contacts are suppressed

Typical overlapping case Non-typical case

Improved tools for

diagnosing/repairing

mesh interfaces


Repair Overlapping Named Selections (16.2)

• Find & Repair Entities (Faces or Edges) that are in multiple named selections (thus causing overlapping zones in output to Fluent or CFX)

• Repair will place original named selections in Overlapping Named Selection folder and set “Send to Solver” to No. Repaired Named Selections will be at bottom of list. Only operates on Named Selections that are marked Send to Solver=Yes.


Performance Improvements

• Linux performance: Linux more comparable to Windows

• Other general and model specific performance improvements

0:00:00

0:28:48

0:57:36

1:26:24

1:55:12

2:24:00

2:52:48

Model 1 Model 2 Model 3 Model 4

Tim

e

Average time for several mesh sizes and settings

R16.2 Windows (average) R16.2 Linux (average)

R17 Windows (average) R17.0 Linux (average)


Performance Improvement: Fluent mesh transfer

0

10

20

30

40

50

60

70

Model 1(220 M Cells)


Model 3(79 M Cells)

Model 4(63 M Cells)

Model 5(20 M Cells)

Me

mo

ry (G

B)

Fluent Export Memory Improvement

Memory -Standard Format Memory -Large Model Format

0

500

1000

1500

2000

2500

3000



Model 3(79 M Cells)

Model 4(63 M Cells)

Model 5(20 M Cells)

Tim

e (s

ec)

Fluent Export Speed Improvement

Time -Standard Format Time -Large Model Format

• New option: Large Model Support• Guidelines:

• May want to use with models >10 Million • Models should be read into Fluent in parallel• Number of internal zones, and zone IDs may

change


Better Meshing Status:

• Progress is now reported as parts are meshed in parallel • As a part is meshed the topology (edges, faces, bodies) are highlighted

to show what is being worked on • This can be turned off by unchecking “Highlight”• If user stops meshing, entity will stay highlighted, allowing user to find problematic

geometry easier

Notes:

• If user stops meshing,

parts that have been

meshed are done

• Restarting meshing

resumes with only

unmeshed parts


Folders for Meshing Controls

● Mesh controls can now be grouped for easier organization

● Option: Group All Similar Children, will group all objects based on type

● Options to suppress, rename, nest groups, ungroup, delete objects in group

● Drag and drop capabilities to modify the grouping


Contact match mesh

• Connect mesh at mesh level

• At R17 only works with tet mesh

• Could avoid problems with shared topology

Notes:

• Mesh generated as separate parts

• Use Contact Match controls to match

mesh

• Create Named Selection to inspect

matched mesh

• Node merge can be added as second

step to make mesh conformal


Capped section planes

● Shaded section planes

Shaded or hollow section plane

Plot by body colour or same colour for section plane


Improved diagnostics: Mesh display By Body Connection

Turning wireframe mode on

Default mesh display

Turning on Mesh display by body connection.


Improved diagnostics: Close vertices

• Close Vertices: Checks for vertices that are very close together:

Scale can be adjusted depending on model sizes


Improved ICEM CFD Interactive Blocking

• Interactive ICEM CFD to create initial blocking:

• Often faster way of decomposing model

• Blocking topology stored w/model

If no blocking

exists, it allows

user to create one


Improved ICEM CFD Interactive Blocking

• Now user can adjust sizes, etc. and update mesh using the batch ICEM CFD to reuse the blocking topology

Re-use blocking

in batch mode


Coming in R17.2…

• WB meshing libraries updated to use Fluent Meshing Cutcell R17.2

– Faster more accurate size functions

– Quality improvements

– Defect fixes

• Support for local proximity size function control

• Target Skewness (beta option in R17 ) will become a full feature


Fluent Meshing R17


Main window layout

Help/Hide Ribbon

Detachable Console

Movable Icon Sets

Common Icons with solver

OperationIcons

Display/Selection controls


UI Enhancements @ R17


Updated Tree

Enclosed Region icons now give information• Type (Fluid, Solid, Dead)• Mesh condition (full, partial etc)


CAD import/management (R17.1)

• New CAD Assemblies Import Option– CAD tree retained

– Fast re-import and re-tessellate of parts

– Sort assembly geometry needed for analysis

– A link is maintained for easy updates and design changes

– Face-zone labels preserved for persistent mesh settings

– Allows faster visualisation

• Overall time saving in part management of huge models


Demonstration on Youtube ANSYS Channel


Interactive Join/Intersect operations

• Finding right tolerance for Join/Intersect is sometimes tricky – Interactive Join/Intersect has local Mark and Undo

operations to avoid incorrect joins and improve efficiency

• Icon for Gap closing, Join and Intersect – Easier access to additional gap closing before join Gap


Region Based Volume Meshing

• The ability to fill one or many regions with a volume mesh– Enables different mesh settings per

region

• Partial region meshing (beta)– Ability to partly fill a region, or fill

a remainder of a partly filled region

– Scoped prism, Tet and HexCore

• Support for Quad and Hex meshes in Object based workflow– Allows mix-and-match with WB

Meshing or ICEMCFD Hex meshing


Object based meshing – Quad/Hex support

• Hex and Quad cells are supported in the object tree– Import hex meshes from Workbench meshing

– Very useful for thin regions where stretched hexes can save significant mesh cost

• Cell zone to Boundary zone -stitching– Connecting to boundary zones defined at the cell boundary

– Use /boundary/remesh/stitch-with-preserve-boundary


Parallel Volume Meshing Capabilities

• The roadmap for CFD meshing is parallel!

– Multi-release, staged development

• Two approaches are available today for parallel meshing with tet and prisms to speed up the task and utilise distributed memory

1. “Region Based” prism/tetmeshing (R16)

2. Auto-decomposed prism meshing with serial tet (R17)


Parallel Prism+ Serial Tet Meshing schematicSu

rfac

e M

esh

Node 0 - Tet

Node 1 - Prism

Node 2 – Prism

Node 3 - Prism

Node 4 - Prism Pri

sm-C

ap S

urf

ace

mes

h

Flu

ent

Solv

er

HD

F5 W

rite

Pri

nci

pal

iner

tia

axis

met

ho

d


Parallel Prism + Serial Tet Meshing efficiency

7.6

10.55

7.6

5.86.4

4.43.8

4.7

3.62.8

3.8

2.62.5

3.6

2.52.3

3.32.6

0

2

4

6

8

10

12

Combustor Landing Gear Oilplatform

Min

ute

s

Scoped Parallel Prism + tet + lean data structure (beta)

R16 -no lean Serial 2-dpm 4-dpm 8-dpm 16-dpm

Combustor4.7 M Prism3.5 M Tet

Landing Gear7.0 M Prism5.7 M Tet

Oil platform3.6 M Prism5.7 M Tet


Parallel Prism Meshing I/O (beta)

• Writing out HDF5 format using DrivAer (prism only) mesh

35

1812

4

99

0

20

40

60

80

100

120

Serial 4-node 8-node 16-node

Seco

nd

s

Case write of 11.2 million prism

Hdf5 Meshor –t1


Native Polyhedral Meshing

• Efficiency (strong model dependency)– 2-3 times less memory and 2-3 times faster compared to serial tet generation

and serial poly conversion in Fluent Solver

• Optimal creation– Supporting Baffles, Local refinements, Size Function and scoped prism settings

– Selective concavity handling reduces the mesh size compared to converted polys with 15-30 % while reducing size change

– Polyhedral driven quality criteria during initial tet generation and many other additional post quality enhancing operations

• Limitations– Only object driven meshing (tree)

– Zone-specific prisms are not supported

– Cannot mix with other mesh methods

• Not included in region based meshing

– Quad boundary is not supported


Native Poly Meshing

BOI

• Landing gear with BOI– 8.1 million poly cells – R16.1 (poly in BETA)

• Worst initial OS = 0.99– 3 cells over 0.9 fixed by ANM

• Time = 32 min• Peak memory 12 GB

– R17.0• Worst OS = 0.9• Time = 20 min• Peak memory 12 GB

BOI


Several HexCore Enhancements (beta)

• Octree instead of Cartesian– Enabled via TUI command

/mesh/hexcore/controls/octree

– 10 – 50% speedup and memory reduction

• Strong model dependency

• Size Field driven instead of Buffer layers– More accurate size distribution

– Support of BOI

• Advanced peel layer control – More accurate gap creation leading to a

reduction in the number of tets and consistently good quality


• Remove large gaps between solids

• Create missing geometry

Prepare: • Naming objects and zones• May merge solids of same material • Extract Features• Define Size Function• Define prism layers• Define Material Points

Fluent Meshing

SCDM

STL

Fluent Meshing Scheme (Batch)

• Extract Contact Pairs • Used for Mapping and NCIs

Fluent Meshing

Scripted Automatic Meshing for Complex CHT

Generate Main and Secondary Fluid Regions with Prism Layers

Coming Soon as an ACT!


Erling Eklund Lead Product Manager FBU

WBPolyMeshingForFluent R1.4


Objectives

• The default Fluent Meshing Workbench functionality requires the user to write a journal to make the workflow parametric

– Journal may be a few lines to e.g. mesh volume and smooth for better quality

–But… scripting is always a barrier to entry

• ACT Solution … To optionally or permanently access selective Fluent Meshing technologies within the Workbench environment and workflow

– In particular Native Polyhedral meshing

• To deploy Fluent Meshing technology to non-expert users

• To allow Fluent Meshing users to benefit from the Robust Design process within Workbench


Available at the ACT App Storefor V17.0 and V17.1

– Introduction Video

– Step-by-step instruction including any limitations

•


Comparison with Converted Poly Mesh

Native Poly mesh Converted Poly mesh


ICEM CFD 17.x Highlights


17.x Highlights:

• Improved control of pre-inflation

• MultiZone improvements– 3D MultiZone

– More automation in decomposition

– Improved tools for editing free & swept blocks

– 2D MultiZone from curves

– Improvements in display

• Custom features– Improved toolkit exposure

– Improved output interface for Exodus II for larger models

– Improvements in aligning to existing mesh

• Improved robustness


Improved pre-inflation options:

• Additional pre-inflation settings

• Improved consistency:• Pre & post use similar controls

• Local growth law and height limit factor

• Ability to apply at part, face, or edge level

Upper Plate

Lower Plate

Vane


3D MultiZone

• New option for 3D MultiZone:– Easier than 2 step approach in past of 2D Blocking

then 3D Fill

– More similar to option in WB Meshing App

– New option Mapped/Swept Decomposition to help control level of decompostion

Swept Block

Swept Block

Free Block

Mapped Block


3D MultiZone: Bottom-up approach to ICEM CFD Hexaextended to Swept/Free blocks

• All mapped (structured) blocks

• User is sculptor (need to think through blocking)

Top-Down Blocking: Historical approach to meshing in ICEM CFD


3D MultiZone: Bottom-up approach to ICEM CFD Hexaextended to Swept/Free blocks

Bottom-up Blocking: MultiZone automates blocking (decomposition)

• Any combination of blocks (Mapped, Swept, Free)

• Automation as much as possible

• Leverage block (topology) editing tools to finish (if needed)


3D MultiZone: Comparison of Approaches

Top Down (Sculpting) Bottom Up (Brick laying)

Often easier/faster to get an all hex mesh Faster to get first mesh (but may not be all hex)

Global topology: avoids getting stuck in cornersMore flexibility: Can stop at any time with a valid mesh (but may have free blocks, i.e. tets/pyramids)

Topology is less constrained to CAD, most work is in associating to CAD

Topology is associated (constrained) to CAD, most work is in freeing some of the original constraints.

User can also use a combination of both approaches!


3D MultiZone: Combination of Approaches

Delete Free Block

Simplify Swept to Mapped

Convert Swept to Mapped

Block from faces for middle region

Block from faces to connect to base

Extrude Block

Update associations

Improve shape

MultiZone Blocking

Mesh


Free/Swept/Mapped Block Editing Features

• Merge Vertices

• Merge Faces

• Split Blocks

• Convert free block face to mapped/free

• Imprint faces

Swept Block

Swept Block

Free Block

Mapped Block


Block editing: Merge vertices

• Merge vertices added for swept block (collapses out side faces)

• Merge vertices added for free blocks


Block editing: Merge faces

• New option for block faces:– Allows selection of free or mapped faces

attached to free blocks

– Limitations for other types or faces

• Face corners (traditional options):– Only works on mapped faces attached to

mapped blocks


Block editing: Split Free Blocks

• Easier tools to split up free blocks to make swept or mapped regions:


Block editing: Convert Blocks

• Tools to convert 3D blocks:– Mapped

– Swept

– Free

– Y-Block

• Tools to convert faces:– Convert free block face to free

– Convert free block face to mapped

• Tools to alter blocks:– Reverse sweep direction

– Merge sheet w/free blocks

• Tools to edit mesh method for blocks:– 3D free block mesh type

– Free face mesh type

• Almost all of these operations have been improved in 17.0

• Convert free block face to mapped is new operation to help convert free blocks to swept or mapped.


Block editing: Imprint

• Imprint Loops into free face

• Use the 2 faces to slice the free block forming a mapped region

1 Free Block


2D Blocking from curves:

• 2D Blocking can be generated directly from curves

• Use combination of free and mapped blocks to help models w/large length scale differences


Improvements in projected edge shape

• Projected edge shape does a better job of showing mesh representation


Associate edge or face to reference mesh

Given a pre-meshed edge or face,

associate edge->curve or face-

>surface and use Reference Mesh to use existing mesh.


Improved toolkit exposure:

• Removed product licensing restrictions, now toolkits have separate display options:

– Settings->Products replaced by Settings->Tools


Thank you

r17.x pre-processing update - ansys · 1 © 2016 ansys, inc. october 6, 2016 ansys confidential...

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